Transjugular intrahepatic portosystemic shunt (TIPS) procedures are typically performed to attempt to connect the portal and hepatic veins in the liver in an effort to reduce portal hypertension (i.e. high blood pressure of the portal system of the liver). Typical systems and methods for performing TIPS procedures have shortcomings that do not solve the central problems associated with the procedure. The procedure is currently performed by using fluoroscopic images to introduce a long needle called a “Colapinto” needle into the hepatic vein. Once in place, a blind needle stick is made through the hepatic vein wall, through the liver parenchyma toward the portal vein in an attempt to connect the two vessels.
Conventional TIPS systems use a puncture needle that is encased in a large hollow guide needle bent at an angle that is appropriate for most TIPS procedures. The correct shunt path is determined by blindly passing the puncture needle in the perceived direction of the target vessel and slowly retracting it while applying negative pressure to a syringe attached to the puncture needle or its hollow cannula and checking to see if blood is returned, indicating a vessel has been struck. The procedure continues by placing a guide-wire through the puncture needle and confirming its path using fluoroscopy. Once confirmed, a series of dilators and/or a balloon is inflated over the guide-wire and a stent is inserted and expanded to establish a permanent connection, thereby relieving the hypertension condition.
The connection or “shunt” can relieve symptoms and extend life until a suitable donor liver can be arranged or other measures taken as deemed necessary. TIPS procedures, although minimally invasive, are generally performed in an interventional radiology suite using high doses of fluoroscopy and contrast agents. Furthermore, TIPS procedures and can take an extended period of time, as the procedure is essentially “blind”, and includes minimal possibilities to accurately direct the TIPS needle to the correct location.
The Colapinto needles used to perform TIPS procedures have two degrees of freedom, namely a cranial-caudal sliding motion and an axial rotation of the needle about its long axis. The puncture needle may be extended some distance from the end of the Colapinto needle, adding a third degree of freedom. TIPS procedures can be demanding in that the needle trajectories are often incorrect. Frequently, multiple needle passes may be made, which can take an extended amount of time even with experienced physicians. In some cases, it may not be possible to establish the shunt. Furthermore, X-ray use (e.g., from fluoroscopy devices) can cause a large radiation dose to both patients and physicians. Large doses of contrast agent may also be delivered to the patient during TIPS procedures, which may interfere with kidney function and have other side effects. Such procedures may also use significant hospital resources and be costly.
Accordingly, a need exists for systems, methods and devices for TIPS procedures that eliminate or minimize doses of harmful radiation and/or contrast agents as well as improve the accuracy of these procedures and reduce the time required to perform such procedures.